1.
The first question is about the tense we should use after "as soon as". In a sentence such as this:
I had left when the phone rang.
you need to use the past perfect in the second clause to show which action came first and which – second. However, when you use “as soon as”, the sequence is clear and it is normally a matter of preference which one to use, so both your examples will be correct. In American English the preference would normally be past simple. The past perfect would emphasize the fact that one action was complete before the other one occurred. (an explanation given in Grammar for Teachers by Andrea DeCapua)
2.
In the second pair of examples they are both correct again. It is unnecessary to use past perfect because the time is mentioned and the sequence of events is clear. Also, the actions are described in the order in which they occurred. You can use the past perfect if you want, to emphasize that one was before the other.
3.
The third question was about the sentence
He said that the moment he first met her, he felt something special and began to keep a diary.
The actual words the man said must have been:
"The moment I first met her, I felt something special and began to keep a diary."
When you report his words and begin with “He said”, the entire phrase shifts one tense back and becomes:
He said that the moment he had first met her, he had felt something special and had begun to keep a diary.
Although this is the grammatically correct sentence, it is very common that the past simple does not become past perfect in indirect speech. When reporting, native speakers tend to make present tenses past ("I am studying" - "She said she was studying") but very often do not care to make the past tenses perfect, as grammar books always teach us we should.
That is what makes both these sentences correct: "He said that the moment he first met her, he felt something special and began to keep a diary." and “He said that the moment he had first met her, he had felt something special and had begun to keep a diary.” (have a look at the end of this page)
As @snailboat said in comments:
Shifting to the present tense in the middle of a narrative is a use of the so-called "historical present". It has the effect of making a story more vivid, more immediate. I think if you search the site for that term you'll be able to find some more detailed descriptions of it.
Most stories are set in the past, and as such are properly spoken in past tense. However, speaking of the past in present tense can indicate that the speaker's recollection is so vivid that the speaker almost feels transported back to the moment of the events. Speaking in present tense is also common trick in storytelling to a create greater sense of immediacy for the listener, in hopes that the listener will imagine the events in present tense, as if the listener were a witness to the events as they are happening.
Best Answer
Not quite.
I wish I ate meat indicates that, for whatever reason, she does not eat meat. Technically, this could be by choice, it could be for medical reasons, etc.
I wish I could eat meat indicates that she is prevented from eating meat, whether she chooses to or not. Possibly her religion forbids it, or she has a health problem that prevents it, either way there is some external factor or force that prevents her from eating meat.
Most likely from the context, she is vegetarian by choice, as this is a common phrase when someone is abstaining. Another example would be "I don't drink" to indicate abstaining from alcohol.
Technically, the first phrase doesn't indicate the reason she does not eat meat; it simply states that she doesn't. The second phrase indicates both that she does not eat meat, but also indicates that there's a factor or force preventing it. Without that indication, the assumption is that it is by choice.